Mixture of battery tuning and firmware innovations could deliver 3 to 5 times longer battery life

While the poaching of Microsoft Corp.'s (MSFT) top scientists by Google Inc. (GOOG) and other rivals has made headlines in recent years, Microsoft still appears to have plenty of brainpower in the stable at its long-term R&D unit, Microsoft Research.

Today, Mr. Chandra's work is still focused on mobile devices, but on one of the mobile industry's biggest shortfalls -- battery life. Today’s most powerful smartphones and tablets require daily recharges. Mr. Chandra's goal is highly ambitious and specific -- to deliver smartphone technology that takes battery life under average daily use from around a day or two to a full week.

Microsoft Research senior scientist Ranveer Chandra wants smartphones that can go for a week without a recharge. [Image Source: Microsoft]

In other words, he wants to make smartphone battery life around 3 to 5 times greater than what is currently available.

You can’t just wait for the best battery technology to come along. We can make a lot of progress because systems today don’t use battery intelligently.

His most innovative idea is to produce a battery with two or more individual cells or segments tuned for different power consumption levels. Today's smartphones have a single battery that supplies current at what is considered an "average" load. In smartphone terms, typically this means an average use case when the phone is on.

Heat and electrical leakages diminish any battery from its ideal theoretical capacity. Batteries see the lowest level of waste -- and highest level of energy efficiency -- when operating at the current they're tuned to. The problem when it comes to smartphones is that at low power (standby), the hardware is typically drawing too little current and wastes more power, as a result. On the flip side, when under an unusual heavy load (e.g. a pocket 3D-game) the phone may draw more than the battery's standard current, causing it to heat up and waste power.

Mr. Chandra's initial concept involves using two lithium ion batteries -- one for standby current levels; the other for current levels at higher performance. In tests this seemingly simple change increase a smartphone's battery life by 20 to 50 percent.

While he didn't go into details, it's reasonable to extrapolate that eventually the principle could be extended to subdivisions of the active power cell into multiple current levels -- perhaps one for very low power activities (reading texts, etc.), one for medium power activities (internet browsing), and one for very graphically intensive activities (HD video, 3D gaming). Also, as standby power is typically consumed while the phone is sitting in your pocket (poorly ventilated) and active power is typically consumed when the phone is sitting in your hand (well ventilated), the standby cell could be tuned to operate under poor ventilation conditions.

II. Smarter Multitasking

While that technology hasn't made it to the commercial phase yet, Mr. Chandra's firmware work has started to trickle into use. One of his projects is E-Loupe -- a piece of OS firmware that essentially does predictive multitasking. It watches app usage in order to predict which currently unused apps aren't likely to be used for some time. Those apps are then either paused or slowed down. E-Loupe uses a cloud database of a plethora of Windows users in order to generate smarter predictions, even before your device learns the quirks of your particular usage patterns.

Microsoft's E-Loupe uses the cloud to optimize multitasking power consumption.

It will take a lot of work to achieve the dynamite goal of a 3-5 times battery life improvement in the timeframe Mr. Chandra desires -- the next several years. But Microsoft appears to be in striking distance of those goals, if he is able to properly mature his current mixture of hardware (battery tuning) and firmware (predictive task pausing/backgrounding, CPU clockspeed control).

If Windows Phones could run for a full week on a single charge under normal use and Microsoft held the patents to make that capability exclusive, that could be a game changer for Microsoft's smartphone ambitions.

Some might for better battery life. I certainly wouldn't... I think 1080p is enough for a 5" phone, 1440p would be useful at 6". But I'm sure I'll end up with a 1440p phone in a year or so since the industry will move in that direction and I won't avoid a flagship device because it's high resolution.